Erik Simonsen/Getty(WASHINGTON) -- On Thursday President Obama’s nominee to lead the CIA said that the idea of an outside check on each decision to kill an American citizen abroad who is believed to be a terrorist is “worthy of discussion.”

John Brennan, who is currently Obama’s counter-terrorism advisor and believed to be the architect of the administration’s drone strike policy, said he would consider the suggestion by Sen. Angus King, Jr., I-Maine, that the government set up a type of court in which someone outside of the executive branch would have a chance to double-check the evidence against the American man or woman marked for death by drone strike.

“Having the executive being the prosecutor, the judge, the jury and the executioner all in one is very contradictory to the traditions and the laws of this country,” King said. “A soldier on the battlefield doesn’t have time to go to court, but if you’re planning a strike over a matter of days, weeks or months, there is an opportunity to at least go to someone outside of the executive branch body…in a confidential and top-secret way [and] make the case that this American citizen is an enemy combatant. At least that would be some check on the activities of the executive.”

Brennan, appearing before the Senate Intelligence Committee for his open confirmation hearing, said King’s proposal was “certainly worthy of discussion” and had been previously considered, but said that the decision to take out a terrorist is not solely based on past guilt and is therefore inherently unlike normal due process.

“The decisions that are made to take action [are made] so that we prevent future action, so that we protect American lives,” Brennan said. “The actions that we take on the counter-terrorism front, again, are to take actions against individuals where we believe that the intelligence base is so strong and the nature of the threat is so grave and serious, as well as imminent, that we have no recourse except to take this action that may involve a lethal strike.”

As reported by The New York Times, Brennan has long presided over the “kill list” for President Obama, reviewing al Qaeda operatives marked for death and advising the president on which strikes he should approve. The president doesn’t currently have to get the okay from a federal court before a strike, according to a March 2012 speech by Attorney General Eric Holder, because “‘due process’ and ‘judicial process’ are not one in the same, particularly when it comes to national security.”

Two days before Brennan’s hearing, NBC News published a Department of Justice document summarizing the administration’s legal justification for killing American citizens abroad as part of the president’s obligation to “national self-defense.”

The 16-page document says that the government can take out an American citizen who is a “senior operational leader of al Qaeda or an associated force” in foreign countries as long as:

"An informed, high-level official of the U.S. government has determined that the targeted individual poses an imminent threat of violent attack against the United States.”

Capturing the targeted individual is “infeasible,” and the U.S. would continually monitor whether capture becomes feasible.

The operation “would be conducted in a manner consistent with applicable law of war principles.”

However, the document says that by “imminent threat,” the DOJ does not mean the U.S. government actually has to have “clear evidence that a specific attack on U.S. persons and interests will take place in the immediate future,” but rather a “broader concept of imminence” must take into consideration terrorists who are “continually planning” attacks and the typically limited window during which a lethal operation may be conducted.

In his testimony Thursday, Brennan did not offer his own definition of “imminent,” but twice repeated that King’s idea should be considered.

“What’s the appropriate balance between executive, legislative and judicial branch responsibilities in this area?” he said.